As stated in the above-identified U.S. Pat. No. 7,662,188, during the described procedure and following the formation of an upward channel in the bone leading to the sinus floor of a patient, there is a simultaneous and controlled lifting and lateral separation of an exposed portion of the sinus membrane from the sinus floor to form an open pocket between the sinus floor and the sinus membrane. Such sinus pocket formation is accomplished using a sinus lifting tool or instrument. The present invention is directed to a preferred form of that instrument.